Costa back in the goals as Chelsea give boss Mourinho much-needed win

Costa ended a six-match barren spell, prompting chants of "we are staying up" and "Jose Mourinho", as the Barclays Premier League champions secured a fourth win in their 13th Barclays Premier League game of the season to edge away from the foot of the table.

Three years to the day since Rafael Benitez was installed as interim successor to Champions League-winning boss Roberto di Matteo, Mourinho was desperate to end a run of three straight league losses in front of the watching Roman Abramovich.

Mourinho, banned from the stadium for the defeat at Stoke, was the subject of the first managerial vote of confidence in Abramovich's 12-year ownership on October 5.

The caveat of the board's support was that results had to improve and Chelsea have now won three times in eight games since

Here, Costa converted Cesc Fabregas' quick free-kick for just his fourth goal of the season and first since last month's defeat of Aston Villa.

Costa had earlier been conspicuous by his absence when Eden Hazard - some of his effervescence restored - twice crossed well, while he wasted two other chances, reminiscent of Fernando Torres.

He blasted over Pedro's cutback and then was denied by John Ruddy two minutes before the break.

Kurt Zouma also hit the bar after Chelsea had gone 1-0 up.

Norwich had opportunities, with John Terry blocking a Sebastien Bassong effort and Asmir Begovic saving well from Robbie Brady.

And, as with many Chelsea matches this season, there were penalty controversies.

Costa and Bassong grappled at one point and Willian went down under a Jonny Howson challenge before escaping a foul for bundling over Brady at the other end.